JP4054625B2

JP4054625B2 - Drilling tools

Info

Publication number: JP4054625B2
Application number: JP2002208453A
Authority: JP
Inventors: 北村　　精男; 田内　　宏明
Original assignee: GIKEN LTD.
Current assignee: GIKEN LTD.
Priority date: 2002-07-17
Filing date: 2002-07-17
Publication date: 2008-02-27
Anticipated expiration: 2022-07-17
Also published as: JP2004052282A

Description

【０００１】
【発明の属する技術分野】
本発明は、地盤を掘削する先端爪が着脱可能に設けられるとともに、オーガの先端部に着脱自在に設けられる掘削工具に関する。
【０００２】
【従来の技術】
一般に、硬質地盤を掘削して縦穴を形成する装置としてアースオーガが知られている。このアースオーガには、掘削地中へ空気や水を流し込む流路を有する管状のオーガ（オーガ軸）と、オーガに螺旋状に設けられたスクリューと、オーガの先端部に着脱自在に接続されて硬質地盤を掘削する掘削工具（オーガヘッド）とが備えられている。
【０００３】
オーガヘッド１００は、図４に示すように、オーガに接続される接続部１０１と、接続部１０１の先端部に着脱自在に取り付けられ、地盤を掘削する先端爪１０２と、先端爪１０２を接続部１０１に固定する固定ピン１０３とを備えている。
【０００４】
接続部１０１は、先端爪１０２を保持する保持部１０４と、保持部１０４の後面から後方（図では上方）に向かって突出し、オーガに嵌め合わされる嵌合部１０５とからなり、内部には、オーガの流路と連通し、空気や水を掘削土中に導く逆Ｔ字状の連通孔１０６が設けられている。
【０００５】
保持部１０４の外側面には、連通孔１０６の出口側の開口部１０６ｂが配置されている。つまり、保持部１０４には、保持部１０４の径方向に沿って連通孔１０６が貫通している。そして、保持部１０４には、連通孔１０６の出口側の開口部１０６ｂを開閉する開閉弁１０７が設けられている。
保持部１０４の先端部には、先端爪１０２が接続される嵌合穴１０８と、切欠１０９とが設けられている。そして保持部１０４には、テーパ部分１０４ｂを嵌合穴１０８から外側面まで貫通するピン孔１１０が、保持部１０４の径方向に沿った直線上に並んで設けられている。
【０００６】
嵌合部１０５は、オーガに設けられた凹部に嵌め合わされるように、オーガの凹部よりもいくらか小さめの略同形状に形成されている。また、嵌合部１０５の後面には、連通孔１０６の入口側の開口部１０６ａが配置されている。
【０００７】
先端爪１０２は、地盤を掘削する爪部１１１と、爪部１１１の後面から突出し、接続部１０１の嵌合穴１０８に嵌め込まれる凸部１１２とを備えている。
凸部１１２には、凸部１１２が接続部１０１の嵌合穴１０８に嵌め込まれた際に接続部１０１のピン孔１１０と連接する貫通孔１１３が、前記ピン孔１１０とほぼ同径で貫通している。そして、接続部１０１の２本のピン孔１１０と凸部１１２の貫通孔１１３とが連接した際に、固定ピン１０３をピン孔１１０及び貫通孔１１３に挿通すれば、接続部１０１と先端爪１０２とを固定できる。
【０００８】
この先端爪１０２を接続部１０１から取り外す際には、固定ピン１０３を取り外した後、接続部１０１の切欠１０９に、取り外し補助用の先の細い部材（例えばドライバー等）の先端部を入れ込むことで、接続部１０１と先端爪１０２の接合を弱めて、先端爪１０２を取り外している。
【０００９】
【発明が解決しようとする課題】
しかしながら、先端爪１０２の交換等のための取り外しは、掘削が行われた後に行われるので、掘削により接続部１０１と先端爪１０２の間に入り込んだ土砂が、接続部１０１と先端爪１０２の接合を強めてしまい、取り外し補助用の部材ではなかなか外れにくいのが現状であった。
【００１０】
本発明の課題は、先端爪の取り外しを容易に行うことのできる掘削工具を提供することを目的とする。
【００１１】
【課題を解決するための手段】
請求項１記載の発明は、例えば図２に示すように、
地盤を掘削するオーガの先端部に接続される掘削工具（例えばオーガヘッド１）であって、
前記オーガの先端部に接続される接続部（例えば接続部２）と、
前記接続部の先端部に着脱自在に設けられ、地盤を掘削する先端爪（例えば先端爪６）とが備えられ、
前記接続部の先端部には、前記先端爪が接続される嵌合穴（例えば嵌合穴２５）が設けられ、
前記接続部の後端部には、軸方向に沿って貫通するとともに、前記嵌合穴と連通する連通孔（例えば連通孔２３）が設けられ、
前記嵌合穴には、前記接続部と前記先端爪との隙間を封じるシール部材（例えばオーリング６６）が備えられることを特徴としている。
【００１２】
請求項１記載の発明によれば、連通孔と嵌合穴とが連通しているので、先端爪を接続部から取り外す際に、連通孔から棒状の部材を挿通すれば、この棒状の部材が先端爪の後面を押して、先端爪を押し出すことができる。つまり、先端爪と接続部との間に土砂が入り込んで、両者の接合が強まっていたとしても、直接先端爪を押し出すことができ、容易に先端爪を取り外すことができる。
【００１３】
請求項２記載の発明は、請求項１記載の掘削工具において、
前記オーガの内部は気体もしくは液体の流路とされ、
前記連通孔は、前記オーガの流路と連通し、前記流路を流れる気体もしくは液体を前記接続部の外部に導くことを特徴としている。
【００１４】
従来のような切欠を利用して先端爪を取り外す構成であれば、掘削時に切欠内に土砂が詰まって、取り外し補助用の部材を切欠内に入れ込むのにも、土砂を切欠から除去しなければならず容易ではなかったが、請求項２記載の発明によれば、掘削中においては、オーガの流路を流れる空気や水が、連通孔を介して接続部の外部に導かれる。つまり、掘削中には連通孔内に空気や水が流れているので、連通孔が土砂により詰まることはなく、従来のように土砂等を除去しなくとも、容易に先端爪を取り外すことができる。
【００１５】
【発明の実施の形態】
以下、この発明の実施の形態について、図１〜図３の図面を参照しながら説明する。
【００１６】
本実施の形態のオーガヘッド（掘削工具）は、アースオーガの先端部に備えられて、地盤を掘削するものである。ここでアースオーガは、掘削地中へ空気や水を流し込む流路を有し、先端部にオーガヘッドが接続される管状のオーガ（オーガ軸）と、オーガに螺旋状に設けられたスクリューとを備える。
そして、この流路を流れる液体や気体を掘削土中に混入することで、掘削土を柔らかくでき、効率よく掘削できる。
【００１７】
オーガヘッド１は、図１及び図２に示すように、オーガに接続される接続部２と、接続部２の側部から側方に向かって延び出る一対の羽根３と、地盤を掘削する掘削爪４と、各羽根３に３つずつ取り付けられ、オーガの正回転方向に向かって突出するように掘削爪４を着脱自在に保持するホルダ部５と、接続部２の先端部に着脱自在に取り付けられ、地盤を掘削する先端爪６と、先端爪６を接続部２に固定する固定ピン７とを備えている。
【００１８】
接続部２は、羽根３及び先端爪６を保持する保持部２１と、保持部２１の後面から後方（図では上方）に向かって突出し、オーガスクリューに嵌め合わされる嵌合部２２とからなり、この接続部２の後端部には、軸方向に沿って貫通するとともに、オーガの流路と連通し、流路を流れる空気や水を接続部２の外部に導く逆Ｔ字形状の連通孔２３が設けられている（図２）。
【００１９】
保持部２１は、オーガヘッド１がオーガに取り付けられて掘削される際には、その外側面が掘削土中に臨む。そして、保持部２１は、上部の外形が円柱状であり、この円柱状部分２１ａの先端から先方（図では下方）に向けて外径が小さくなるようにテーパが形成されている。そして、円柱状部分２１ａとテーパ部分２１ｂの境目近辺には、連通孔２３の出口側の開口部２３ｂが配置される。つまり、保持部２１には、保持部２１の径方向に沿って連通孔２３が貫通し、保持部２１の外側面に連通孔２３の出口側の開口部２３ｂが配置される。
【００２０】
そして、保持部２１には、連通孔２３の出口側の開口部２３ｂを開閉する開閉弁２４が、保持部２１の外側面から開閉弁２４をはみ出させないように窪んだ開閉弁収納部２４ａに設けられている。この開閉弁２４には、閉じる方向に付勢力が働いており、連通孔２３内に空気や水が流入すると開閉弁２４は空気や水に押されて開き、掘削土中に空気や水が流れ込む。そして、開閉弁２４は、連通孔２３内に空気や水が流れ込まないと付勢力により、連通孔２３の出口側の開口部２３ｂを閉じて、連通孔２３内に土砂が入り込むことを防止する。
【００２１】
また、保持部２１の先端部には、先端爪６が接続される嵌合穴２５が設けられている。この嵌合穴２５は、先端爪６の凸部６２（後述）よりもいくらか大きめの略同形状の窪みであり、先端爪６の凸部６２が嵌め込まれる。そしてこの嵌合穴２５は、連通孔２３と繋がって連通しており、嵌合穴２５と連通孔２３によって接続部２に先後方向（軸方向）に沿って貫通する孔を形成している。
そして、保持部２１には、テーパ部分２１ｂを嵌合穴２５から外側面まで貫通する２本のピン孔２６が、保持部２１の径方向に沿った直線上に並んで設けられている。２本のピン孔２６のうち少なくとも一方のピン孔２６には、固定ピン７の板部７２（後述）を、保持部２１の外側面からはみ出させないように収納する固定ピン収納凹部２６ａが設けられている。
【００２２】
嵌合部２２は、オーガの先端部に設けられた凹部に嵌め合わされるように、オーガの凹部よりもいくらか小さめの略同形状（ここでは、略六角柱状）に突出して形成されている。そして嵌合部２２の対向する面には、オーガスクリューとオーガヘッド１とを固定するヘッド固定ピンが挿通される溝２２ａが設けられている。そして、嵌合部２２の後面には、連通孔２３の入口側の開口部２３ａが配置される。つまり、オーガにオーガヘッド１が取り付けられると、オーガの凹部を形成し、かつ流路の開口部が配置されるオーガの内面に、嵌合部２２の後面が臨んで接触することとなる。これにより、オーガの流路と連通孔２３の入口側の開口部２３ａとが連接し、オーガの流路からの水や空気が、連通孔２３により掘削土中まで導かれる。
【００２３】
先端爪６は、図２に示すように、地盤を掘削する爪部６１と、爪部６１の後面から後方に向かって突出し、接続部２の嵌合穴２５に嵌め込まれる凸部６２とを備えている。
爪部６１は、上部の外形が円柱状であり、この円柱状部分６１ａの下端から先が尖るように円錐状に形成されている。
【００２４】
凸部６２は、爪部６１の後面から後方に向かって突出する第一凸部６３と、第一凸部６３の後面から後方に向かって円柱状に突出する第二凸部６４とからなる。
【００２５】
第一凸部６３は、基端部分が円柱状であるとともに、先端部分が多角柱状に形成されている。この第一凸部６３には、先端爪６の凸部６２が接続部２の嵌合穴２５に嵌め込まれた際に接続部２の２本のピン孔２６と連接する貫通孔６３ａが、前記ピン孔２６とほぼ同径で貫通している。また、第一凸部６３の基端部分の外周面には、周方向に沿って溝６３ｂが形成されており、この溝６３ｂにはオーリング６５が嵌め合わされる。
第二凸部６４の外側面には周方向に沿って溝６４ａが形成されており、この溝６４ａにはシール部材としてのオーリング６６が嵌め合わされる。そして、先端爪６が接続部２に取り付けられた際には、この第二凸部６４の後面が連通孔２３に臨むこととなり、連通孔２３の入口側の開口部２３ａから棒状の部材を挿入すれば、棒状の部材の先端部が第二凸部６４の後面に接触することができる。
【００２６】
固定ピン７は、接続部２に先端爪６が取り付けられた際に、接続部２のピン孔２６及び先端爪６の貫通孔６３ａに挿通されて、接続部２と先端爪６とを固定するものである。この固定ピン７は、図３に示すように、ピン孔２６及び貫通孔６３ａの内径よりもいくらか外径が小さい略円柱状の固定部７１と、固定部７１の一端部に設けられ、固定部７１よりも外径の大きい略円板状の板部７２と、固定部７１の両端部にそれぞれ取り付けられるオーリング７３とを備えている。
【００２７】
固定部７１の両端部には、オーリング７３が取り付けられる溝７１ａが設けられている。また、固定部７１の板部７２側の端部には、固定ピン７がピン孔２６及び貫通孔６３ａに挿通された際に、板部７２側から抜けるのを防止する断面Ｃ字状の抜け止め材８が設けられている。
板部７２は、固定ピン７がピン孔２６及び貫通孔６３ａに挿通された際に固定部７１の他端部側から抜けるのを防止するものである。
【００２８】
オーリング６５、６６、７３は、例えば樹脂やゴム等で形成された弾性を有する円環状の部材である。このオーリング６５、６６、７３を先端爪６の第一凸部６３、第二凸部６４、固定ピン７に設けていることで、先端爪６を接続部２に取り付けた場合や、固定ピン７を接続部２及び先端爪６に取り付けた場合に、先端爪６と接続部２との隙間や、固定ピン７と接続部２、先端爪６との隙間を封鎖して、これら隙間に土砂が入り込むことを防止できる。また、先端爪６の第二凸部６４に取り付けられたオーリング６６は、連通孔２３から流れる空気や水等の漏れも防止できる。
【００２９】
次に、先端爪６を接続部２に着脱する際の手順について説明する。
【００３０】
先端爪６を接続部２に取り付ける際、先ず作業者は、先端爪６の貫通孔６３ａと接続部２のピン孔２６とが直線状に並ぶように、先端爪６の凸部６２を接続部２の嵌合穴２５に嵌め合わせる。そして、作業者は、固定ピン７を接続部２のピン孔２６及び先端爪６の貫通孔６３ａに挿通し、接続部２と先端爪６とを固定し、先端爪６の取り付けを完了する。
【００３１】
その後、オーガヘッド１がオーガスクリューに取り付けられて、掘削が行われた後、摩耗した先端爪６の交換タイミングとなると、作業者は、オーガスクリューからオーガヘッド１を取り外して、先端爪６の交換を開始する。
【００３２】
先ず、作業者は、固定ピン７がピン孔２６及び貫通孔６３ａから押し出されるように、棒状の部材で、固定ピン７の先端側（板部７２が設けられた端部とは反対側）を押す。固定ピン７が押し出されると、作業者は、連通孔２３の入口側の開口部２３ａから棒状の部材を挿通し、棒状の部材の先端で先端爪６の後面を押し、先端爪６の凸部６２を接続部２の嵌合穴２５から押し出し、先端爪６を接続部２から取り外す。これにより先端爪６の取り外しが完了する。
【００３３】
以上のように、本実施の形態のオーガヘッド１によれば、連通孔２３の入口側の開口部２３ａから棒状の部材を挿通すれば、この棒状の部材が先端爪６の後面を押して、先端爪６を押し出せるので、先端爪６と接続部２との間に土砂が入り込んで、両者の接合が強まっていたとしても、直接先端爪を押し出すことができ、容易に先端爪を取り外すことができる。
また、オーリング６５、６６、７３によって土砂が入り込むことを防止されているので、固定ピン７や先端爪６の取り外しが容易に行うことができる。また、洗浄等も容易に行うことができる。
【００３４】
なお、本発明は上記実施の形態に限らず適宜変更可能であるのは勿論である。例えば、本実施の形態では、オーリング６５、６６、７３は、接続部２に取り付けられる部材（先端爪６、固定ピン７）に設けられる構成であったが、接続部２側にオーリングを設ける構成であってもよい。また、各隙間に土砂等の侵入を防止するものであればオーリングでなくとも、如何なるものでもよく、例えば、各隙間を封印するシール部材やパッキン部材などが挙げられる。
【００３５】
【発明の効果】
請求項１記載の発明によれば、先端爪を接続部から取り外す際に、連通孔から棒状の部材を挿通すれば、この棒状の部材が先端爪の後面を押して、先端爪を押し出すことができる。つまり、先端爪と接続部との間に土砂が入り込んで、両者の接合が強まっていたとしても、直接先端爪を押し出すことができ、容易に先端爪を取り外すことができる。
請求項２記載の発明によれば、掘削中においては、オーガの空洞を流れる空気や水が、連通孔を介して接続部の外部に導かれる。つまり、掘削中には連通孔内に空気や水が流れているので、連通孔が土砂により詰まることはなく、従来のように土砂等を除去しなくとも、容易に先端爪を取り外すことができる。
【図面の簡単な説明】
【図１】本発明を適用した実施の形態のオーガヘッドの全体図を表す斜視図である。
【図２】図１のオーガヘッドを表す側断面図である。
【図３】図１のオーガヘッドに備わる固定ピンを表す正面図である。
【図４】従来のオーガヘッドを表す側断面図である。
【符号の説明】
１オーガヘッド（掘削工具）
２接続部
６先端爪
２３連通孔
２５嵌合穴[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an excavating tool in which a tip claw for excavating the ground is detachably provided and detachably provided at a tip portion of an auger.
[0002]
[Prior art]
In general, an earth auger is known as a device for excavating hard ground to form a vertical hole. The earth auger is detachably connected to a tubular auger (auger shaft) having a flow path for flowing air and water into the excavation area, a screw spirally provided on the auger, and a tip of the auger. An excavation tool (auger head) for excavating the hard ground is provided.
[0003]
As shown in FIG. 4, the auger head 100 includes a connecting portion 101 connected to the auger, a tip claw 102 that is detachably attached to a tip portion of the connecting portion 101, and a tip portion 102 that connects the tip claw 102 to the connecting portion. And a fixing pin 103 to be fixed to 101.
[0004]
The connecting portion 101 includes a holding portion 104 that holds the tip claw 102, and a fitting portion 105 that protrudes rearward (upward in the drawing) from the rear surface of the holding portion 104 and fits into the auger. An inverted T-shaped communication hole 106 that communicates with the auger flow path and guides air and water into the excavated soil is provided.
[0005]
An opening 106 b on the outlet side of the communication hole 106 is disposed on the outer surface of the holding unit 104. That is, the communication hole 106 passes through the holding portion 104 along the radial direction of the holding portion 104. The holding unit 104 is provided with an on-off valve 107 that opens and closes the opening 106 b on the outlet side of the communication hole 106.
The front end portion of the holding portion 104 is provided with a fitting hole 108 to which the front end claw 102 is connected and a notch 109. The holding portion 104 is provided with pin holes 110 penetrating through the tapered portion 104b from the fitting hole 108 to the outer side surface along a straight line along the radial direction of the holding portion 104.
[0006]
The fitting part 105 is formed in substantially the same shape somewhat smaller than the concave part of the auger so as to be fitted into the concave part provided in the auger. An opening 106 a on the inlet side of the communication hole 106 is disposed on the rear surface of the fitting portion 105.
[0007]
The tip claw 102 includes a claw portion 111 that excavates the ground, and a convex portion 112 that protrudes from the rear surface of the claw portion 111 and is fitted into the fitting hole 108 of the connection portion 101.
A through hole 113 connected to the pin hole 110 of the connecting portion 101 when the convex portion 112 is fitted into the fitting hole 108 of the connecting portion 101 penetrates the convex portion 112 with substantially the same diameter as the pin hole 110. ing. When the two pin holes 110 of the connecting portion 101 and the through hole 113 of the convex portion 112 are connected, if the fixing pin 103 is inserted into the pin hole 110 and the through hole 113, the connecting portion 101 and the tip claw 102 are provided. And can be fixed.
[0008]
When removing the tip claw 102 from the connection portion 101, after removing the fixing pin 103, the tip portion of a thin member (such as a screwdriver) for assisting removal is inserted into the notch 109 of the connection portion 101. Thus, the joint between the connecting portion 101 and the tip claw 102 is weakened, and the tip claw 102 is removed.
[0009]
[Problems to be solved by the invention]
However, since the removal for exchanging the tip claw 102 is performed after excavation is performed, the earth and sand that has entered between the connection portion 101 and the tip claw 102 by excavation joins the connection portion 101 and the tip claw 102. The current situation is that it is difficult to remove with a member for assisting removal.
[0010]
An object of the present invention is to provide an excavation tool capable of easily removing a tip claw.
[0011]
[Means for Solving the Problems]
The invention according to claim 1 is, for example, as shown in FIG.
An excavation tool (for example, an auger head 1) connected to the tip of an auger excavating the ground,
A connecting portion (for example, connecting portion 2) connected to the tip of the auger;
A tip claw (for example, a tip claw 6) that is detachably provided at the tip of the connecting portion and excavates the ground, is provided.
A fitting hole (for example, fitting hole 25) to which the tip claw is connected is provided at the tip of the connection part,
The rear end portion of the connection portion is provided with a communication hole (for example, a communication hole 23) that penetrates along the axial direction and communicates with the fitting hole .
The fitting hole is provided with a seal member (for example, an O-ring 66) that seals a gap between the connection portion and the tip claw .
[0012]
According to the first aspect of the present invention, since the communication hole and the fitting hole communicate with each other, if the rod-shaped member is inserted from the communication hole when the tip claw is removed from the connecting portion, the rod-shaped member is By pushing the rear surface of the tip nail, the tip nail can be pushed out. That is, even if earth and sand enter between the tip claw and the connecting portion and the joint between them is strengthened, the tip claw can be pushed out directly, and the tip claw can be easily removed.
[0013]
The invention according to claim 2 is the excavation tool according to claim 1,
The inside of the auger is a gas or liquid flow path,
The communication hole communicates with a flow path of the auger and guides gas or liquid flowing through the flow path to the outside of the connection portion.
[0014]
If the tip claw is removed using a conventional notch, the earth and sand will be clogged during excavation and the removal aid must be removed from the notch to insert the removal aid into the notch. According to the second aspect of the invention, air and water flowing through the flow path of the auger are guided to the outside of the connection portion through the communication hole. In other words, air and water are flowing in the communication hole during excavation, so the communication hole is not clogged with earth and sand, and the tip claw can be easily removed without removing the earth and sand as in the prior art. .
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS.
[0016]
The auger head (excavation tool) of the present embodiment is provided at the tip of the earth auger and excavates the ground. Here, the earth auger has a flow path through which air or water flows into the excavation site, and has a tubular auger (auger shaft) whose tip is connected to an auger head, and a screw provided spirally on the auger. Prepare.
And by mixing the liquid and gas which flow through this flow path in excavation soil, excavation soil can be made soft and can be excavated efficiently.
[0017]
As shown in FIGS. 1 and 2, the auger head 1 includes a connecting portion 2 connected to the auger, a pair of blades 3 extending from the side portion of the connecting portion 2 toward the side, and excavation for excavating the ground. Three claws 4, three attached to each blade 3, a holder portion 5 that detachably holds the excavation claws 4 so as to protrude in the forward rotation direction of the auger, and a detachable portion at the tip of the connection portion 2 A tip claw 6 that is attached and excavates the ground and a fixing pin 7 that fixes the tip claw 6 to the connecting portion 2 are provided.
[0018]
The connection portion 2 includes a holding portion 21 that holds the blade 3 and the tip claw 6, and a fitting portion 22 that protrudes rearward (upward in the drawing) from the rear surface of the holding portion 21 and is fitted to an auger screw. The rear end portion of the connection portion 2 penetrates along the axial direction, communicates with the flow path of the auger, and has an inverted T-shaped communication hole that guides air and water flowing through the flow path to the outside of the connection portion 2. 23 is provided (FIG. 2).
[0019]
When the auger head 1 is attached to the auger and excavated, the outer surface of the holding unit 21 faces the excavated soil. And the holding | maintenance part 21 is a taper so that an outer diameter may become small toward the front (downward in the figure) from the front-end | tip of this cylindrical part 21a in the outer shape of the upper part. An opening 23b on the outlet side of the communication hole 23 is disposed near the boundary between the cylindrical portion 21a and the tapered portion 21b. That is, the communication hole 23 passes through the holding part 21 along the radial direction of the holding part 21, and the opening 23 b on the outlet side of the communication hole 23 is arranged on the outer surface of the holding part 21.
[0020]
The holding portion 21 is provided with an opening / closing valve 24 that opens and closes the opening 23b on the outlet side of the communication hole 23 in an opening / closing valve storage portion 24a that is recessed so as not to protrude from the outer surface of the holding portion 21. It has been. The on / off valve 24 is energized in the closing direction. When air or water flows into the communication hole 23, the on / off valve 24 is pushed by the air or water to open, and the air or water flows into the excavated soil. . The on-off valve 24 closes the opening 23 b on the outlet side of the communication hole 23 by an urging force unless air or water flows into the communication hole 23, thereby preventing dirt and sand from entering the communication hole 23.
[0021]
Further, a fitting hole 25 to which the tip claw 6 is connected is provided at the tip of the holding portion 21. The fitting hole 25 is a hollow having substantially the same shape that is somewhat larger than a convex portion 62 (described later) of the tip claw 6, and the convex portion 62 of the tip claw 6 is fitted therein. The fitting hole 25 is connected to and communicated with the communication hole 23, and the fitting hole 25 and the communication hole 23 form a hole penetrating in the connecting portion 2 along the front-rear direction (axial direction).
The holding portion 21 is provided with two pin holes 26 penetrating the taper portion 21b from the fitting hole 25 to the outer side surface along a straight line along the radial direction of the holding portion 21. At least one pin hole 26 of the two pin holes 26 is provided with a fixed pin storage recess 26 a for storing a plate portion 72 (described later) of the fixed pin 7 so as not to protrude from the outer surface of the holding portion 21. ing.
[0022]
The fitting portion 22 is formed so as to protrude into a substantially the same shape (here, substantially hexagonal column shape) somewhat smaller than the concave portion of the auger so as to be fitted into the concave portion provided at the tip portion of the auger. A groove 22 a into which a head fixing pin for fixing the auger screw and the auger head 1 is inserted is provided on the opposing surface of the fitting portion 22. An opening 23 a on the inlet side of the communication hole 23 is disposed on the rear surface of the fitting portion 22. That is, when the auger head 1 is attached to the auger, the rear surface of the fitting portion 22 comes into contact with the inner surface of the auger that forms the concave portion of the auger and in which the opening of the flow path is disposed. Thereby, the flow path of the auger and the opening 23a on the inlet side of the communication hole 23 are connected, and water and air from the flow path of the auger are guided to the excavated soil through the communication hole 23.
[0023]
As shown in FIG. 2, the tip claw 6 includes a claw portion 61 for excavating the ground, and a convex portion 62 that protrudes rearward from the rear surface of the claw portion 61 and is fitted into the fitting hole 25 of the connection portion 2. ing.
The claw portion 61 has a cylindrical outer shape, and is formed in a conical shape so that the tip is sharp from the lower end of the cylindrical portion 61a.
[0024]
The convex portion 62 includes a first convex portion 63 that protrudes rearward from the rear surface of the claw portion 61 and a second convex portion 64 that protrudes rearward from the rear surface of the first convex portion 63.
[0025]
The first convex portion 63 has a base end portion in a columnar shape and a tip end portion formed in a polygonal column shape. The first convex portion 63 has a through hole 63a that is connected to the two pin holes 26 of the connecting portion 2 when the convex portion 62 of the tip claw 6 is fitted into the fitting hole 25 of the connecting portion 2. It penetrates with the same diameter as the pin hole 26. A groove 63b is formed along the circumferential direction on the outer peripheral surface of the base end portion of the first convex portion 63, and an O-ring 65 is fitted into the groove 63b.
A groove 64a is formed in the outer surface of the second convex portion 64 along the circumferential direction, and an O-ring 66 as a seal member is fitted into the groove 64a. And when the front-end | tip nail | claw 6 is attached to the connection part 2, the rear surface of this 2nd convex part 64 will face the communicating hole 23, and inserts a rod-shaped member from the opening part 23a by the side of the inlet of the communicating hole 23 If it does, the front-end | tip part of a rod-shaped member can contact the rear surface of the 2nd convex part 64. FIG.
[0026]
The fixing pin 7 is inserted into the pin hole 26 of the connecting portion 2 and the through-hole 63a of the leading end claw 6 when the leading end claw 6 is attached to the connecting portion 2 to fix the connecting portion 2 and the leading end claw 6. Is. As shown in FIG. 3, the fixing pin 7 is provided at a substantially cylindrical fixing portion 71 having an outer diameter somewhat smaller than the inner diameters of the pin hole 26 and the through hole 63a, and one end portion of the fixing portion 71. A substantially disc-shaped plate portion 72 having an outer diameter larger than 71 and O-rings 73 attached to both ends of the fixed portion 71 are provided.
[0027]
Grooves 71 a to which O-rings 73 are attached are provided at both ends of the fixing portion 71. Further, at the end portion of the fixing portion 71 on the plate portion 72 side, when the fixing pin 7 is inserted into the pin hole 26 and the through hole 63a, the C-shaped cross-section is prevented from coming off from the plate portion 72 side. A stop material 8 is provided.
The plate portion 72 prevents the fixing pin 7 from coming off from the other end side of the fixing portion 71 when the fixing pin 7 is inserted into the pin hole 26 and the through hole 63a.
[0028]
The O-rings 65, 66, 73 are annular members having elasticity formed of, for example, resin or rubber. By providing the O-rings 65, 66, 73 on the first convex portion 63, the second convex portion 64, and the fixing pin 7 of the tip claw 6, when the tip claw 6 is attached to the connecting portion 2, the fixing pin 7 is attached to the connecting portion 2 and the tip claw 6, the gap between the tip claw 6 and the connecting portion 2 and the gap between the fixing pin 7, the connecting portion 2 and the tip claw 6 are sealed, and earth and sand are sealed in these gaps. Can be prevented from entering. Further, the O-ring 66 attached to the second convex portion 64 of the tip claw 6 can prevent leakage of air, water, etc. flowing from the communication hole 23.
[0029]
Next, a procedure for attaching / detaching the tip claw 6 to / from the connection portion 2 will be described.
[0030]
When attaching the tip claw 6 to the connecting portion 2, first, the operator connects the convex portion 62 of the tip claw 6 to the connecting portion so that the through hole 63 a of the tip claw 6 and the pin hole 26 of the connecting portion 2 are aligned in a straight line. 2 is fitted into the fitting hole 25. Then, the operator inserts the fixing pin 7 into the pin hole 26 of the connecting portion 2 and the through hole 63a of the tip claw 6, fixes the connecting portion 2 and the tip claw 6, and completes the attachment of the tip claw 6.
[0031]
Thereafter, after the auger head 1 is attached to the auger screw and excavation is performed, when the worn tip claw 6 is replaced, the operator removes the auger head 1 from the auger screw and replaces the tip claw 6. To start.
[0032]
First, the operator uses a rod-like member so that the fixing pin 7 is pushed out from the pin hole 26 and the through hole 63a, and the tip side of the fixing pin 7 (the side opposite to the end where the plate portion 72 is provided). Push. When the fixing pin 7 is pushed out, the operator inserts a rod-like member through the opening 23a on the inlet side of the communication hole 23, pushes the rear surface of the tip claw 6 with the tip of the rod-like member, and the convex portion of the tip claw 6 62 is pushed out from the fitting hole 25 of the connection part 2, and the tip claw 6 is removed from the connection part 2. Thereby, the removal of the tip claw 6 is completed.
[0033]
As described above, according to the auger head 1 of the present embodiment, if a rod-like member is inserted from the opening 23a on the inlet side of the communication hole 23, the rod-like member pushes the rear surface of the tip pawl 6 to Since the nail 6 can be pushed out, even if earth and sand enter between the tip nail 6 and the connecting portion 2 and the joint between them is strengthened, the tip nail can be pushed out directly and the tip nail can be easily removed. it can.
Moreover, since the earth and sand are prevented from entering by the O-rings 65, 66 and 73, the fixing pin 7 and the tip claw 6 can be easily removed. Further, cleaning and the like can be easily performed.
[0034]
It is needless to say that the present invention is not limited to the above embodiment and can be modified as appropriate. For example, in the present embodiment, the O-rings 65, 66, and 73 are configured to be provided on members (tip claws 6 and fixing pins 7) that are attached to the connection portion 2. The structure to provide may be sufficient. Further, any material other than O-rings may be used as long as it prevents the entry of earth and sand into each gap, and examples thereof include a seal member and a packing member that seal each gap.
[0035]
【The invention's effect】
According to the first aspect of the present invention, when removing the tip claw from the connecting portion, if the rod-like member is inserted through the communication hole, the rod-like member can push the rear surface of the tip claw and push out the tip claw. . That is, even if earth and sand enter between the tip claw and the connecting portion and the joint between them is strengthened, the tip claw can be pushed out directly, and the tip claw can be easily removed.
According to the second aspect of the present invention, during excavation, air and water flowing through the cavity of the auger are guided to the outside of the connection portion through the communication hole. In other words, air and water are flowing in the communication hole during excavation, so the communication hole is not clogged with earth and sand, and the tip claw can be easily removed without removing the earth and sand as in the prior art. .
[Brief description of the drawings]
FIG. 1 is a perspective view showing an overall view of an auger head according to an embodiment to which the invention is applied.
FIG. 2 is a side sectional view showing the auger head of FIG.
3 is a front view illustrating a fixing pin provided in the auger head of FIG. 1. FIG.
FIG. 4 is a side sectional view showing a conventional auger head.
[Explanation of symbols]
1 auger head (excavation tool)
2 Connection part 6 Tip nail 23 Communication hole 25 Fitting hole

Claims

A drilling tool connected to the tip of an auger excavating the ground,
A connecting portion connected to the tip of the auger;
Provided detachably at the tip of the connection part, and provided with a tip claw for excavating the ground,
A fitting hole to which the tip claw is connected is provided at the tip of the connection portion,
The rear end portion of the connection portion is provided with a communication hole penetrating along the axial direction and communicating with the fitting hole .
An excavation tool , wherein the fitting hole is provided with a seal member that seals a gap between the connection portion and the tip claw .

The excavation tool according to claim 1,
The inside of the auger is a gas or liquid flow path,
The communication hole communicates with a flow path of the auger, and guides gas or liquid flowing through the flow path to the outside of the connection portion.